hungerford etal



1956 G. P. HUNGERFORD ET AL ,734,513

METHOD AND APPARATUS FOR MAKING TOBACCO SHEET MATERIAL 2 Sheets-Sheet 1Filed April 10. 1951 5 sF RR Vl GEM E T L mm" 4% v w m N T P T A nw BNQN WN Q mdE 1956 G. P. HUNGERFORD'ET AL 2,734,513

METHOD AND APPARATUS FOR MAKING TOBACCO SHEET MATERIAL Filed April 10.195i 2 Sheets-Sheet 2 FIG.2

FIG. 5

WET FILM FORMING SURFACE TOBACCO DUST DRY J6 as 59 APPLY FILM FORMING\LAYER & 6 204 APPLY TOBACCO DUST FIG. 6 160 G DOCTOR DRY BRUSH UNDERSIDE0F WEB 220 0 DYE Sm REMOVE UNDERSIDE DRY AND OUT LOOSE 0F was I DUSTPROCESSING PACKAGING OR 0 2,29 INVENTORS J82 2 2 GORDON P. HUNGERFORDJOHN II WILLIAMSON United States Patent METHOD AND APPARATUS FOR MAKINGTOBACCO SHEET MATERIAL Gordon P. Hungerford and John T. Williamson,Brooklyn,

N. Y., assignors to American Machine 62 Foundry Company, a corporationof New Jersey Application April 10, 1951, Serial No. 220,174 28 Claims.(Cl. 131-140) This invention relates to improved tobacco sheets, films,webs, strips and filaments, and to improved methods of producing thesame.

The manufacturer of tobacco products generally buys tobacco in the formof whole leaves as removed from the tobacco plant by the farmer. Inprocessing this tobacco, the stem is frequently first removed and thenfurther processing proceeds as desired. In the case of a cigarettemanufacturer, this processing includes aging, blending, casing andcutting the strip, which is the tobacco leaf portion or portionsremaining after removal of the stem, into shreds and then drying,cooling and screening the shredded tobacco, followed by packaging. Inall these operations, which involve much handling of the tobacco, wastefines and dust are formed. At the present time these waste materials,stems, field scrap (farm damaged leaves), fines and dust haveessentially no value to the tobacco manufacturer, and are sold tomanufacturers of fertilizers, insecticides, and others who use Wastetobacco material in their products, at a fraction of a cent per pound.Much of this waste tobacco material is of good quality from a smokingstandpoint. Indeed it is believed that this waste tobacco materialcontains a disproportionately high percentage of the very best qualitysmoking tobacco, since the latter comprises the thinnest, lightest, mostfriable leaves which would most readily break up into fine particles anddust on handling. These high quality fines are useless not only becauseof their physical form. A technique for processing this good tobaccointo a form which would render it usable in smoking articles withoutessential change in its smoking characteristics would therefore beattractive to a tobacco manufacturer because it would increase theyield, and of course reduce manufacturing costs.

it has been suggested previously that tobacco sheets and films be madeby wet milling a mixture of tobacco in water to form therefrom a slurrywhich can be converted, as by any well-known casting and drying method,into continuous self-supporting sheets and films.

Other attempts to solve the problem of forming a satisfactory tobaccosheet material could be cited, such as by forming tobacco paper usingwell-known paper making techniques. However, despite these attempts,little success has been achieved, and to our knowledge, none of theseprocesses has ever been used commercially.

The present invention constitutes a solution to the problem ofconverting tobacco materials into webs, films, sheets or filaments whichcan be used in the same manner as natural leaf tobacco in tobaccoproducts such as cigarettes, cigars and the like. Films and webs,strips, sheets and filaments, made in accordance with our invention, areelastic, flexible, tough, self-supporting and continuous, and possessdry and wet strengths comparable to that of natural leaves or pieces oftobacco, and'in general retain substantially all naturalcharacteristicsand properties of tobacco, including color, aroma, and ESL? 9, 3

smoking. This is necessarily true, since in accordance Patented Feb. 14,1956 gether into the form of a sheet or strip in a novel manneraccording to the invention by a small proportion of a film formingmaterial, preferably a specially developed food adhesive, and does notchange the characteristic properties of the tobacco thus processed. Itwill be evident, therefore, that the invention alters only the physicalform of the tobacco used as the raw material.

The resulting tobacco sheet material has a high ratio of surface area tomass which causes it to burn more completely than natural tobacco of thesame type would when used in smoking articles. This results in asmoother, milder, less irritating smoke.

The characteristic mildness of the smoke from tobacco sheets or stripmade according to the invention is especially significant when certainharsh, low grades of tobacco are used as the raw material. Thus, theinvention enables a quality improvement in low grade tobacco sufficientto permit the use of the tobacco sheets or strip produced thereby inhigh quality smoking articles.

The strong, flexible nature of the reconstituted tobacco sheet producedin accordance with the invention yields long shreds, when used in acigarette blend, thus tending to minimize the quantity of objectionableshorts which fall out of the end of a cigarette or get onto a smokerstongue, and which may tend to cause non-uniform cigarettes. Theinvention therefore, contributes to decreased manufacturing costs bysimplifying plant operations, and by reducing the amount of good tobaccomaterial, which is presently discarded as waste primarily because itsphysical form makes it unusable in the blend. In addition, the inventioneffects aquality improvement in cigarettes, since cigarettes containingshreds of tobacco or strip made in accordance with the invention, haveless tendency to lose shorts from theends than have cigarettescontaining only natural tobacco shreds. It has also been observed thatcigarettes containing tobacco sheet or web material strip made inaccordance with the invention are milder, smoother, and less irritatingthan standard blend cigarettes. It is believed that this results fromthe poly-particulate structure of our novel strip which gives a veryhigh ratio of surface to mass and extreme porosity, providing readyignition and more complete burning. If desired, whole leaf tobacco ortobacco strip may be used in forming our novel tobacco sheet or filmmaterial. V

It is an object of our invention to provide an apparatus for an improvedmethod of making tobacco sheets, strips,

Webs, films or filaments, wherein fine tobacco particles or tobacco dustare adhered to both faces of a web of film forming material and form anintegral part of the composite tobacco material produced.

It is a further object of our invention to provide an apparatus for animproved method of making self-supporting, continuous flexible tobaccosheets, webs and the like in which a layer of tobacco dust is coatedwith a thin layer of a film forming material, the exposed surface ofwhich is also coated with tobacco dust to form a composite tobacco sheetmaterial consisting primarily of tobacco dust.

The inventionfurther consists in the provision of an improved method ofincreasing the yield of tobacco by improving the physicalcharacteristics of certain types of tobacco which .normally areunsuitable for handling and processing into smoking articles byconverting such tobacco into thin, self-supporting, tough, porous sheetform in which such tobacco in small particle size is adhered to bothsurfaces of a thin web of film forming material to form thereby acomposite {tobacco sheet material consisting principally of tobacco.

it is a further object of the invention to produce novel smokingarticles, such as cigarettes, containing as a part of the cigarettetobacco filler shredded tobacco sheet material or strip produced inaccordance with the invention. Such cigarettes are milder, smoother, andless irritating than standard blend cigarettes. This is believed to bedue to the poly-particulate structure of the tobacco sheet material orstrip which gives a very high ratio of surface to mass and extremeporosity, providing ready ignition and more complete burning.

The invention also consists in the provision of apparatus for and methodof forming tobacco sheet materials, webs, films, filaments and the likeby applying tobacco dust to a moistened surface to which the tobaccodust adheres, after which a thin layer of a suitable film formingmaterial is applied to the layer of tobacco, and tobacco dust is appliedto the exposed surface of the web of film forming material, which isthen dried, the sheet or web material thus produced consisting of acentral thin layer of film forming material having substantiallypermanently adhered thereto on both of its surfaces substantialquantifies of tobacco dust. The sheet material thus produced can be cutinto desired lengths and formed into shreds or filaments suitable foruse in the manufacture of cigarettes or used in sheet form in themanufacture of cigars and like smoking articles.

It is a further object of the invention to provide a novel type ofimproved tobacco sheet or web material.

With these and other objects not specifically mentioned in view, theinvention consists in certain features which will be hereinafter fullydescribed, and then set forth in the claims hereunto appended.

In the accompanying drawings, which form a part of this specification,and wherein the several reference characters designate the same or likeelements:

Fig. 1 is a side elevation of a preferred form of apparatus according tothe present invention, supporting or framing means being omitted;

Fig. 2 is a sectional view taken on line 22 of Figure 1;

Fig. 3 is a sectional view taken on line 3-3 of Figure 1;

Fig. 4 is an end elevation as seen from line 4-4 of Fig. 1;

Fig. 5 is a view showing diagrammatically a modified method of producingour novel tobacco sheet material; and

Fig. 6 is a view showing diagrammatically a modified method of finishingour novel tobacco sheet material and preparing it for use.

Referring to the drawings, Figure 1 shows a preferred form of apparatusfor forming the novel tobacco sheet material in accordance with theinvention, and for carrying out the steps covering the preferred methodof our invention. Numeral 10 designates a device for forming a wettingsolution or liquid wetting material which is applied to the top surfaceof endless belt 12, after which tobacco dust is substantiallyimmediately applied thereto as by blowing the dust thereupon. Anysuitable mixing device may be used for forming wetting solution 15. Thiscan be a vertical mixer similar to that illustrated in De Huff Patent1,781,321, issued November 11, 1930. However, any other conventionaltype of mixer may be used.

A substantially uniform layer of fine tobacco particles or tobacco dustis adhered to belt 12. A method, which has been found satisfactory foradhering fine tobacco particles to belt 12 is to wet belt 12, asdescribed hereinafter. It has been found that this technique insuresthat fine tobacco or tobacco dust coated upon belt 12, will clingthereto and form a substantially uniform layer. This is necessary in anapparatus such as shown in Figure 1, where tobacco dust is depositedupon the exposed surface of the lower lap of belt 12. It is also highlydesirable in a case where a longer belt 12 is used and tobacco dust isapplied to the upper lap thereof. This is due to the fact that if aloose layer of tobacco dust were applied to belt 12, during thesubsequent operation of spraying a layer of film forming material uponthe layer of tobacco dust, the latter in all probability would bedispersed, or a large proportion thereof would be removed from belt 12,and hence the desired results would be unobtainable. In the apparatussuch as shown and in performing the preferred method of the invention, asubstantially uniform continuous layer of tobacco is adhered to belt 12and very satisfactory results are secured.

Solution 15 is piped into a container 14 and is pumped or flows bygravity to a device 20 of suitable design, which atomizes it and spraysit upon belt 12 preferably driven continuously. Device 20 in theillustrated embodiment travels back and forth relative to belt 12 inapplying wetting solution 15 thereupon. If desired, a stationaryspraying mechanism provided with a plurality of stationary spray headsso disposed as to apply a substantially uniform coating of solution 15on belt 12, could be used.

When sprays are used as application means, it may be desirable torecover the spray droplets which do not adhere to the belt surface. Thismay be done by a hood 20a surrounding device 20 connected to a suitableairdroplet separating device by a suitable conduit.

In order to control the amount of wetting solution 15 deposited on belt12, a suitable metering device 13 of conventional design is employed.This may be a metering pump or the combination of a flow meter with acontrol valve. Compressed air, supplied through conduit 22 in knownmanner to device 29, atomizes the solution for application upon belt 12in a uniform thin layer. In order to secure uniform distribution ofwetting solution on belt 12, device 20 is mounted for move ment back andforth across belt 12. in the apparatus illustrated, the desired movementof device 20 is secured by means of an interrupted thread drive shaft 24which engages with and drives carriage 26 supporting device 20. Shaft 24is driven by a motor or other suitable source of power during theoperation of the apparatus. As shown in Figure l, spraying device 20 islocated beneath belt 12. This arrangement makes it possible to use ashorter belt and conserve space. Obviously, if desired, belt 12 could belonger, and wetting solution if could be applied to the upper lapthereof instead of the lower lap, as shown, and the same resultsobtained.

Wetting solution or liquid wetting material is principally a watersolution and its use is designed primarily to provide a wetted surfaceto which a layer of tobacco will cling until it is covered with a layerof suitable film forming substance, referred to hereinafter in detail.lution 15, as used herein, contains a small amount of low viscositycarboxymethylcellulose. to assist in bond ing the tobacco particles tothe main strength-giving film. This may be omitted if desired. Theconcentration of CMC used in solution 15 preferably ranges between (1.5and 1 /2% by weight and the thickness of the film solntion 15 appliedpreferably ranges between 3 and 10 mils. But other concentrations andthicknesses can be used. if desired, and in order to aid solution 15 inwetting belt 12, a small quantity of a suitable detergent is used as aningredient of solution 15. One-tenth of one percent of Dreft, asynthetic detergent, in the solution 15. has proven to be satisfactory.

Belt 12 moves in the direction of arrow A. It is supported upon drivingpulley or drum 28 and driven pulley or drum 30 on shafts 32, 34,respectively and has an upper lap U and a lower lap L. Shaft 32 isdriven continuously from a motor or other suitable source of power andat a speed commensurate with the proper practice of the invention.

Following the application of solution 15 to belt 12, the belt moves to atobacco dust applying zone where a de vice, designated generally 36,applies tobacco dust or fine particles of tobacco to the wetted portionof the surface of belt 12. Tobacco dust in quantity greater than thatwhich will adhere to the wetted surface of belt 12 is blown thereupon byan air blast nozzle 38 fed by a conduit 40 from a conventional type ofdry material feeding mechanism 42. The device illustrateddiagrammatically in Figure 1 is a Dry Chemical Feeding Mechanism made byWallace and Tiernan Co., Belleville, N. J. Any other conventional typeof feeder may be employed as long as it can be used for the elficientand effective distribution and application of dust onto belt 12. Blower41 connected in the operating conduit system of feeding mechanism 42,forces air through chamber 44 where tobacco dust, fed by a screwconveyor element (not shown) in mechanism 42, is taken up and sprayed orblown upon the, wetted portion of belt 12. It has been found that an airvelocity ranging between 3300 and 5000 cu. ft./min. at the nozzle tipgives satisfactory results. An electric vibrator 46 attached to thehopper 48 of feeding mechanism 42, assists in the proper movement oftobacco dust to the feeding screw conveyor element (not shown) in hopper48. As the result of the operation of device 36, a substantiallycontinuous unbroken layer of tobacco. dust is deposited upon the wettedportion of the surface of belt 12 where it remains as the movement ofbelt 12 brings it to and passes it through the next operating stationwhere a thin layer of film forming solution is applied to the tobaccodust adhering to belt 12.

A large excess of tobacco dust is applied by nozzle 38. Dust which doesnot adhere to belt 12 is recovered by a recovery system including a hood45 surrounding nozzle 38, and a suction conduit 49 connected to asuitable air separating unit, such as a conventional Cyclone Separator(not shown), or a bag filter. Dust recovered is returned to hopper 48for re-use. As shown in Figure 1, the nozzle of unit 20 preferably isdirected away from dust applying mechanism 36. This arrangement insuresthat tobacco dust, issuing from nozzle 38, will be substantially free ofthe danger of being coated by wetting solution 15 which might render itless suitable for recycling and re-use.

Spraying or blowing nozzle 38 may be one of a plurality of nozzlesextending transversely across the path of travel of belt 12 or a singlenozzle extending entirely across the path of movement of belt 12. Asshown in the illustrated embodiment, however, it consists of a singlenozzle 38 attached to conduit 40 and mounted on a carriage 50 supportedupon and moved back and'forth relative to belt 12 by interrupted threadshaft 53 of conventional design. See FigureZ. The ends of shaft 53 aresupported in hearings in side frames 6 and 8 of the machine. Attached toone end of shaft 53 is a pulley 57 on which runs a driving belt 59running on a driving pulley (not shown) driven by any suitable source ofpower, as a motor (not shown) or main drive shaft of the apparatus (notshown). Stabilizing rods 55 having their ends attached to frames 6 and8, pass through horizontal parallel bores in carriage 50 and maintainthe latter and nozzle 38 in proper operative position during itscontinuous travel back and forth relative to belt 12 while the apparatusis in operation. The portion of belt 12 which is coated with tobaccodust next moves to a coating zone where a thin layer of a suitable filmforming material is applied over the layer of tobacco.

In forming the novel reconstituted tobacco sheet or web materialdescribed hereinabove, the film forming material used in making the baseweb of our sheet or web material can be any film forming material whichpossesses adequate strength and retains the tobacco particles well. Itis also essential that a film forming material be used which hasadhesive qualities and which on smoking the final reconstituted tobaccosheet or web does not cause an unsatisfacotry taste, aroma or harshness.Suitable film forming materials are water soluble salts ofcarboxymethylcellulose and carboxymethylhydroxyethylcellulose, orcarboxymethylcellulose and carboxymethylhydroxyethylcellulose, which arerespectively cellulose glycolic acid and cellulose hydroxy giycolicacid, the latter two being insoluble in water but which are capable ofbeing formed into stable water dispersions in a manner described incopending application Serial Number 130,858, filed by Newton Heimbach onDecember 2, 1949, for Water Insoluble Coatings, Films, and Adhesives andMethod of Making Same. These dispersions are capable of being cast toform a wet web, which when dried, becomes a self-supporting, waterinsoluble film. The terms CMC and CMHEC where used herein, mean the freeacid forms of cellulose glycolic acid or carboxymethyl cellulose, andcellulose hydroxy glycolic acid or carboxymethyl hydroxyethyl cellulose,respectively.

If desired, a cross linking agent, such as glyoxal may be added toimprove further the water resistance of the already water resistant CMC.If desired, a humectant may be added to the film forming dispersion.

Typical dispersions can be prepared as follows: a A inch diameter streamof a 3.75 percent high viscosity sodium carboxymethylcellulose solutionin water is extruded into about twice its weight of 20 percent sulfuricacid solution. The sodium carboxymethylcellulose solution forms threadswhich are allowed to stand in the acid two hours to complete theacidification of the sodium carboxymethylcellulose. The threads ofreacted carboxymethylcellulose are then removed from the acid by meansof a suitable screen. The insoluble carboxymethylcellulose is thenwashed with a stream of water until the pH 'of a dispersion formed byprocessing a sample of the carboxymethylcellulose threads in a WaringBlendor is 2.4. At this point, the washing may be discontinued. Thecarboxymethylcellulose, which is now in the form of semi-solid, long,gelatinous strands, is then ground in a colloid mill, Waring Blendor, orsimilar device to produce a fine dispersion of carboxymethylcellulose inwater. In general, we may use a. technique similar to that disclosed incopending Heimbach application, Serial Number 130,858, filed December 2,1949, for Water Insoluble goatings, Films, and Adhesives and Method ofMaking ame.

In forming satisfactory aqueous carboxymethylcellulose dispersions, itis found that good results are obtained when the concentration of thesodium salt of carboxymethylcellulose solution ranges between 2 and 8%by weight, and the final sulfuric acid concentration is between 5 and25%. The time of acidification may vary over wide limits, as may thewashing time. The pH of the final carboxymethylcellulose dispersion mayalso vary from about 1.5 to 5.0.

To make a dispersion suitable for coatings, the concentratedcarboxymethylcellulose, prepared as described above, may be diluted tothe desired concentration by the addition of water, and if desired,suitable quantities of a humectant, such as glycerine can be added, andif desired, glyoxal may also be added.

The techniques described for forming aqueous dispersions of celluloseglycolic acid are followed in making aqueous dispersions ofcarboxymethyl hydroxyethyl cellulose which for our purpose hascharacteristics similar to those of cellulose glycolic acid. Asatisfactory dispersion of acid carboxymethylhydroxyethyl cellulose foruse in forming films, web, sheets and the like, was made as follows: Thesodium salt of carboxymethylhydroxyethyl cellulose was dissolved inwater to form a thick paste. Thepaste was extruded through a $1 inchdiameter orifice into 20% sulfuric acid and was permitted to stand inthe acid for two hours. The hardened spaghetti-like threads of theinsoluble acid form of carboxymethyl hydroxyethyl cellulose were removedfrom the acid, drained and washed with running water for twenty minutes.The washed threads were then dispersed in a manner similar to thatdescribed above to form an aqueous dispersion which was formed into awet web which was coated with tobacco dust and dried to form acontinuous reconstituted tobacco sheet and web material.

The amount of film forming material applied depends on the physicalstrength desired in the final sheet or strip. It has been found thatwhen an'amount of dispersion equivalent to 0.8 gram CMC per square footof sheet is used, the dry breaking strength of the final sheet is about700 grams per inch of width. In this sheet the belt wetting solution wasapplied in an amount such that the sheet contained 0.15 gram per squarefoot of low viscosity CMC. This sheet was adequately strong to passthrough the same process and the processing equipment used for naturalleaf tobacco without any significant mechanical degradation. Obviously,if greater or less strength is required, the amount of film formingmaterial may be adjusted to obtain the desired strength.

The dispersion, designated generally 51, is contained in a suitablecontainer 52 having a conduit 54 connected to tube 55 of a metering pump56, the rotor of which (not shown) is driven by a belt 58 from asuitable source of power such as a motor (not shown). Belt 58 runs onpulley 60 attached to rotor shaft 62. Any conventional type of meteringpump may be used so long as a constant quantity of dispersion is forcedthrough conduit 64 to and through nozzle 66 of applying device 70. Thepump shown diagrammatically in Figure 1 may be similar in constructionand operation to that illustrated in U. S. Patent No. 1,848,024 issuedMarch 1, 1932, to Owens, for pumping metered quantities of dispersion 51to nozzle 66. Applying device includes a carriage 68 supporting nozzle66. Carriage 68, which may be similar in construction and operation tocarriage 26, is mounted on interrupted rotary shaft 69 suitablysupported in side frames 6 and 8 of the machine for movement back andforth above belt 12, in order that film forming material may be sprayedby nozzle 66 upon the layer of tobacco particles adhering and clingingto the wetting so lution 15 on belt 12. If desired, a hood (not shown),similar to that used in connection with spraying device 20, may beprovided for recovering sprayed dispersion 51 not actually forming thefilm covering the layer of tobacco particles.

Following the application of the thin layer of film forming material 51,and While it is still wet, belt 12 moves the wet layer into a tobaccodust applying zone where a tobacco dust depositing device, designatedgenerally 72, such as a travelling blowing nozzle 74, applies a heavycoating of tobacco dust to the wet exposed adhesive surface of the layerof film forming material 51.

In the embodiment illustrated in Figure l, nozzle 74 applies tobaccodust to the wet exposed surface of the layer of film forming material 51on the upper lap U of belt 12. Excess tobacco dust is caught by hood 76,attached to the machine frame by brackets 71, and conducted by asuitable suction system including a conduit 78 to the dust air separatorreferred to hereinabove for re-use. It will be noted that hood 76 isprovided with a transverse slot 80 through which nozzle 74 projects intotobacco dust applying position to belt 12 and along which it travels asit moves back and forth across belt 12. The desired movement of carriage75, which supports nozzle 74 in the illustrated embodiment, is securedby an interrupted thread driven shaft 77 of conventional design drivenfrom a suitable source of power continuously during the operation of themachine. Tobacco dust is fed by a vibratory feeder, designated generally82, which is vibrated in known manner during the operation of themachine by a motor 84 attached thereto. Tobacco fed from feeder 82 isdelivered into chute 86 whence it is conducted into blower 88 ofsuitable conventional design, and forced with air delivered by blower 88through conduit 73 and nozzle '74 and onto the surface of the wetexposed surface of the layer of material 51, as stated above.

Belt 12 preferably is provided with a polished impermeable surface. Belt12 as used herein, is made of metal and for that reason is subject toexpansion and contraction during its passage through dryer 90 whichremoves moisture from the composite web carried thereby.

It has been found that unless the dimensions of belt 12 at certainstages of the drying process are controlled, undesirable checks andcracks may be formed in the web W. It is believed that these checks andcracks occur when belt 12, carrying an already solidified Web W, isallowed to continue to rise in temperature, thus expanding the belt.Since the solidified web W adheres firmly to the belt and cannot stretchappreciably before cracking, expansion of belt 12 could cause theobserved cracks.

Since web W is normally solidified and set before it is completely dry,belt 12, carrying web W, normally is exposed to heat aftersolidification of the web takes place, in order to complete the drying.This heating expands the belt and could cause checks and cracks. It hasbeen found that if the belt is heated before it enters the portion ofdryer 90 where the web W has been solidified, the aforementioned checksand cracks are substantially prevented. Therefore, in order to insurethat the composite tobacco sheet material web W will be substantiallyfree of checks and cracks which would be undesirable, means are providedfor heating belt 12 in order to expand it prior to its reaching thepoint in dryer 90 where solidification of web W occurs. As shown inFigure l, dryer 90 may be divided into several zones in which difierentconditions of temperature, air velocity and humidity may exist. Inaddition, individual control of temperature and/or air velocity may beprovided for the spaces faced by both top and bottom of the belt in eachzone. Thus, by adjusting the rate of heat transfer to the side of thebelt not covered by web W and by adjusting temperature and/or airvelocity, the temperature of the belt may be controlled, thus enablingthe prevention of checks and cracks in web W as explained above. Anysuitable conventional type of control valve may be used for securing theproper heat transfer required in each zone I, II and III and controllingthis independently in each zone. A suitable valve, indicated generallyat 21, is a thermally actuated valve, the degree of opening of which iscontrolled by the temperature of the air passing through the exhaustducts of each dryer zone. In the case of a gas fired dryer valves 91control the quantity of gas being burned in each zone.

If desired, the belt may be pie-heated in order to expand it by aheating element suitably mounted on the frame of the machine. Heatingelement 110, which may be of any suitable conventional design, extendstransversely across belt 12, as indicated in Figure l, and when heat isgenerated therein, the heat results in expansion of belt 12 such thatcracks and checks in web Ware prevented, as stated above.

When heating element is provided, the amount of heat transfer to thebelt itself in dryer 90 may be less than when element 110 is notprovided since the desired expansion of belt 12 has already beeneffected by element 110. On the other hand, under some conditions, itmay prove desirable to again heat belt 12 to insure its proper expansionbefore it reaches the point in dryer 90 where web W is solidified.

Located between hood 72 and dryer 90 along the path of travel of belt12, are flexible blades 81, preferably formed of rubber or thin flexiblesteel, which bear against the upper surface of belt 12. The positions ofthe inner edge of each of these blades 81 determine the width of thefinal web W since these blades scrape olf and remove the edge portionsof the web. In this manner, the Width of the web passing into dryer 90is maintained substantially constant.

Blades 81 are mounted on brackets 83 adjustably secured in slots inbrackets 85 suitably attached to the side frames 6 and 8 of the machine.The position of each blade 81 can be adjusted as desired by looseningwing nuts 87, moving brackets 83' inwardly or outwardly, and thentightening the wing nuts in the desired'adjusted position.

Upon emergence of the portion of belt 12 which carries Web W from dryer90, it moves beneath a brushing unit designated generally 120' whichincludes a rapidly rotated brush 122 mounted on a continuously drivenshaft 124, suitably journalled for rotation in the side frames of themachine 6, 8, and driven in any desired manner by a motor or othersource of power (not shown). Unit 120 also includes a hood 126 supportedin any desired manner by the side frames of the machine and extendingtransversely across belt 12. Hood 1-26 preferably has downwardly taperedside, and ends (not shown) and has connected thereto, as indicated inFigure 1, a suction conduit 128 connected to the above referred to airseparator, such that loose tobacco dust and particles, brushed from thetop surface of web W, are conducted from hood 126 through conduit 128and returned for re-use.

After the brushing operation just described, belt 12 moves web W througha moistening device designated generally 140. This device can beemployed for the sole purpose of applying moisture, as by sprayingwater, upon the exposed surface of the brushed composite web W, or, asshown in Figure 1, it can perform the dual function of rehumidifying andapplying a suitable dye to the exposed surface of the web in order thatthe resulting web product may suit the color requirements of themanufacturer who is to use the product. In the embodiment selected forpurposes of illustration, device 140 consists of two sets of spraynozzles, 142 and 144 projecting downwardly from conduits 146, 148respectively, extending transversely of belt 12. The ends of conduits146 and 148 are suitably supported in side frames 6 and 8 of themachine, Figure 3. Conduits 146 and 148 are connected by a Y unit 150 toa mixing valve 160. A conduit 162 connects valve 160 to asource ofsupply of water 163. A conduit 164 connects valve 160 to a source ofsupply of dye 165. Conduit 162 is provided with a metering device 166,and conduit 164 is provided with a metering device 167. In this manner,the metered quantities of water and dye flowing from containers 163 and165 respectively through valve 160 to conduits 146 and 148 can becontrolled as desired by proper manipulation of mixing valve 160. Theflow of dye to nozzles 142 and 144 may be stopped completely. The sameis true with respect to water flowing from container 163. As shown inFigure 1, the flow of water or dye to nozzles 142 and 144 is effected bygravity. Obviously if desired, this could be accomplished by a pump. Acompressed air conduit 168 operatively connected to valve 160 providescompressed air for atomizing the mixture of water and dye, or wateralone, depending upon the fluid flowing into Y unit 150 from containers1,63 and 165, or 163 alone, as the case may be. Compressed air isfurnished to conduit 168 from any suitable conventional source of supply(not shown).

Under some conditions, the degree of drying accomplished in dryer 90 canbe controlled such that web W can be removed from belt 12 withoutremoistening by device 140. Under these conditions, device 140 may beused to apply dye only; or if dye is not required, device 140 may beeliminated entirely.

The moistened composite tobacco sheet or web material W is removed frombelt 12 by means of a conventional type of doctor blade 180. Thecomposite tobacco sheet material web W after being removed from thesurface of belt 12, is moved therefrom onto an endless conveyordesignated generally 190. As shown in Figure 1, located between thedelivery end of belt 12 and the receiving end of conveyor 190, is a dyeapplying device designated generally 182 which consists of a carriage184 mounted for movement back and forth relative to the undersurface ofweb W as the latter moves onto coni6 veyor 190. This movement iseifected by means of amin terrupted threaded, shaft 186 similar inconstruction and operation to shafts 53 and 7 7, which during theoperation of the machine is driven continuously so that so long as web Wis being delivered from belt 12, spraying device 182 applies dye to theundersurface of web W; Of course, if it is not desired to apply dye tothe undersurface of web W, the rotation of shaft 186 is prevented bysuitable means (not shown), and hence the movement of carriage 184 isalso prevented. In order to provide for this operation, means, such as avalve (not shown), are provided for preventing the flow of dye andcompressed air to nozzle 188. Dye is conducted to nozzle 188' throughflexible conduit 189 from a source of supply, such as container 163 anda suitable metering device, similar in construction and operation tometering device 167. Compressed air for atomizing purposes is conductedto nozzle 188 by means of flexible conduit 191 from any suitableconventional source of supply (not shown). Suitable hoods (not shown)may be provided for use with devices 142 and 182 for recovering dyespray droplets, thereby preventing possible waste of the relativelyexpensive dye.

Conveyor preferably comprises an endless travelling belt 192 formed ofcanvas or like material. Belt 192 runs on drums 194 and 196. Drum 194 isattached to driving shaft 198 which is driven in any desired manner asby a motor or from the main shaft of the machine. Shaft 198' isrotatably supported in bearings (not shown) in side frames 6 and 8 ofthe machine. Drum 196 is mounted on a driven shaft 200 also rotatablysupported in side frames 6 and 8 of the machine. Belt 192 carriesmoistened web W through a dryer 202 of suitable conventional design inwhich, as the web passes therethrough, moisture is removed until as theweb leaves the dryer, the desired moisture content is present in theweb. This may be from 10 to 15 moisture by weight. Obviously the dryermay be so adjusted in known manner as to control the amount of moisturecontained in web W as it leaves the dryer and is delivered by conveyor190 to a roller 204 mounted on a continuously driven shaft 206. As web Wis fed positively and continuously from continuously moving conveyor190, it passes beneath a rotating brush 208 supported by a continuouslydriven shaft 210. Shafts 206 and 210 are also rotatably supported inside frames 6 and 8 of the machine. Shaft 206 is driven by a pulley 207on which runs a driving belt 209 running on a driving pulley (not shown)driven from any suitable source of power. Brush 208 performs thefunction of removing from the surface of the composite tobacco sheetmaterial web W any loose particles of tobacco dust which may be presenttherein. These are received Within a hood 212, which is attached to sideframes 6 and 8 of the machine in any suitable manner. A suction conduit214 connected to the air-tobacco separator above referred to deliversall reclaimed tobacco dust to a suitable receptacle for re-use.

After being brushed, web W is passed between a continuously drivenroller 216 mounted on a continuously driven shaft 218 and a coacting,rotating brush 220 at tached to continuously driven shaft 222. Shaft 218is driven by a pulley 217 by a belt 219 running on a suitably drivendriving pulley (not shown). Brush 220 is enclosed in a suction hood 224similar in construction to hood 212, and by means of a suction conduit226, loose tobacco is removed from the under-surface of web W andconducted to the above referred to receptacle (not shown) for re-use. Ifdesired, finished web W may be rolled into reels for further processing.It is preferred, however, to cut it to a desired size since this enablesit to be handled more readily and packed for shipment or for immediateuse in a plant, such as a cigarette factory. As indicated in Figures 1and 4, a gang of equally spaced rotary knives designated generally 229may be used for cutting web W longitudinally in the direction of itstravel. Gang knives 229, shown in Figure 4, is made up of five knives230 secured to continuously rotating shaft 23:2 journalled for rotationin side frames 6 and 8 and driven by means of a pulley 234 and belt 236from a motor or other suitable source of power such as the main driveshaft of the machine (not shown). Obviously more or less knives 230could be used, depending upon the width of strips desired. Increasingthe number of knives 230 and closely spacing them, web W can be cut intofilaments or shreds. Knives 230 coact with grooves in a metal roller238. Roller 238 is mounted on a shaft 240 journalled in side frames 6and 8 and driven in a manner similar to shaft 232. Strips of webs arefurther out into pieces P, such as shown in Figure 4, by means of arotary cutter consisting of a transverse blades 242 mounted on a roller244 secured to shaft 246 having a pulley 248 on which runs a belt 250driven from a suitable source of power (not shown). A ledger blade 252carried by roller 254 on continuously rotated shaft 256 operativelysupported in side frames 6 and S and driven in a manner similar to thatof shaft 246, coacts with blade 242 to cut the pieces which fall into asuitable receptacle (not shown). Since there may be a loosening oftobacco dust particles at the lines of cut as the result of the cuttingoperations of knives 230 and 242, and it is desirable to reclaim suchtobacco dust for further use, it is preferred to provide a suctionreclaiming device indicated generally as 260 having a suction conduit262 operatively associated therewith, which conduit conducts the tobaccodust to the air separator for separation and storage. As shown in Figure1, sheets or pieces of the novel tobacco sheet or web material Pdropping from transverse cutting blade 242, pass between a plate 264 andsuction reclaiming device 260 which has a low suction such that eachsheet or piece P is free to continue its fall, but tobacco dust andparticles are sucked off and collected for re-use in the manner stated.

In some cases, it is desirable to brush the underside of web W before itis dyed in order to avoid uneven dyeing of the underside and therebyinsure uniform coloring thereof. Figure 6 illustrates diagrammaticallythe steps involved and suitable apparatus which can be used in carryingout these steps. In Figure 6, 180 indicates a doctor blade which removesweb W from belt 12, whereupon web W moves through a dryer 261 similar inconstruction and operation to dryer 202, shown in Figure l. Theunderside of web W is then brushed by a brush 220, dye is applied by anapplying device, designated generally 182, described hereinabove, andthe web is then passed through dryer 202. Dried web W upon emerging fromdryer 202, is moved through slitting and cutting device 229, and anyloose fine tobacco particles or dust are removed by device 260 shown inFigure l. The finished sheet material is then packed, or processeddirectly into smoking articles such as cigarettes.

It is believed that the description and operation of the apparatus shownin Figures 1 to 4 inclusive, will make clear the manner in which apreferred method of forming our novel tobacco sheet or web material iseffected. Figure 5 shows a modified form of method for producing ournovel tobacco sheet or web material. In general, the modified method isessentially the same as that described in connection with the apparatusshown in Fig ures l to 4 and is set forth as follows: Referring toFigure 5, a film forming surface similar in construction and operationto belt 12, disclosed in Figure l, is wetted as at 359 with a wettingsolution similar to solution used in the preferred method. Tobacco dustof fine tobacco particles are then applied in excess quantity by asuitable blowing device indicated at 352, which device may be similar inconstruction and operation to that shown in Figures 1 and 2. The excesstobacco dust and/or tobacco particles are recovered in the mannerdescribed above for re-use. The film forming surface is then moved to adrying device indicated at 354 in Figure 5 where the layer of tobaccoclinging to the film forming surface is dried. A thin layer of filmforming material, such as described in the preferred method abovereferred to, is then applied in a uniform thin layer as at 356 by aspraying device, such as device 70, over the dried layer of tobacco dustand/or tobacco particles on the film forming surface. As in thepreferred method described hereinabove, a large quantity of tobacco dustis blown as at 258, by a mechanism similar to device 72 shown in Figure1, upon the wet exposed surface of the layer of film forming material,and the excess quantity of dust or tobacco particles is recovered forre-use. The resulting composite web, consisting of a bottom layer oftobacco dust or particles, an intermediate thin layer of film formingmaterial, and a top layer of tobacco dust and/or particles, is thendried as at 360 as the result of the film. forming surface being passedthrough a suitable dryer such as dryer shown in Figure l. The stepsemployed subsequent to the drying operation are the same as set forth inconnection with the description of the preferred method. The resultingtobacco sheet or web material is then cut to size and either packed forshipment to a processing plant, or used directly in the formation ofsmoking articles. If the material is to be used in the formation ofcigarettes, it is shredded in any suitable manner and admixedwithshredded cigarette tobacco, or can be admixed in sheet or strip formwith cigarette tobacco strip, which mixture is shredded before beingformed into cigarettes.

While several embodiments of the invention have been described, it is tobe understood that the invention is not confined to the specificapparatus or method steps for carrying out the methods set forth hereinby way of illustration, as it is apparent that changes and variationsmay be made therein by those skilled in the art without departing fromthe spirit of the invention or exceeding the scope of the claimshereunto appended.

What we claim is:

1. Apparatus for forming self-supporting continuous tobacco films andsheets comprising a substantially impermeable moving film forming memberhaving a film supporting surface, means for applying a liquid wettingmaterial upon successive portions of said moving surface, a device forapplying finely divided tobacco particles in a continuous layer uponsaid wetted portions of said moving surface, means for applying a sprayof an adhesive film forming material upon said layer of tobaccoparticles adhering to said moving wetted surface, a device for applyinga layer of fine tobacco particles upon the exposed wet surface of saidlayer film forming material on said moving surface, and a dryer locatedin the path of travel of said moving surface for evaporating said liquidwetting material and drying the composite layer thus produced to form acomposite continuous self-supporting tobacco film or sheet.

2. Apparatus for forming self-supporting continuous tobacco sheets andfilms comprising an endless substantially impermeable film formingmember having a film forming surface and having an upper lap and a lowerlap, mechanism for moving said surface continuously, at surface wettingstation located adjacent said lower lap, means for applying a liquidwetting material to said surface of said lower lap as said surface movespast said station, a device for applying finely divided tobaccoparticles to said moving wetted surface of said lower lap as it movesthrough said station, whereby a thin continuous layer of tobaccoparticles adheres to said wetted moving surface, means for applying anadhesive film forming material upon said layer of tobacco particlesadhering to said wetted surface and forming a thin continuous filmcovering and bound to said layer for tobacco particles, :1 device forapplying a layer of fine tobacco particles to the exposed wet surface ofsaid layer of film forming material on said upper lap, a dryer locatedin the path of movement of said upper lap of said moving surface forremoving moisture from said wet composite web thereby solidifying saidcomposite tobacco bearing layer into a self-supporting con- I 13 tinuoustobacco sheet, and means for removing. said dried sheet from saidsurface.

3. The apparatus defined in claiml including a mechanism mountedadjacent said first-named tobacco applying device for heating andexpanding said surface prior to the movement of said wetted tobaccoparticle hearing portions of said moving. surface into the range ofoperation of said means for applying a. spray of film forming materialto said tobacco adhering to said wetted surface.

4. The apparatus definedin claim 1 wherein said dryer includes aplurality of drying zones, the first zone of which applies heat to theunder side of said surface, whereby said film bearing surface isexpanded prior to the passage of the film bearing portions of saidsurface through the remaining zones to prevent cracking and checking ofsaid web as said portions of said surface move through said remainingzones.

5. Apparatus for forming self supporting continuous tobacco films andsheets comprising an endless imperforate band conveyor having a. movingfilm forming surface, means for applying a liquid wetting agent andwetting successive portions of said moving surface therewith, a devicefor applying finely divided tobacco particles in a continuoussubstantially uniform heavy layer upon said wetted portions of saidmoving surface,, said device including suction means for recovering freeexcess fine tobacco particles, means for applying a spray of a filmforming material upon said layer of tobacco particles adhering to saidmoving wetted surface, a device for applying a substantially uniformheavy layer of fine tobacco particles upon the exposed wet surface ofsaid layer of film forming material on said moving surface, adryingmeans located in the path of travel of said moving surface for removingsaid liquid wetting agent and drying the composite layer thus producedto form a composite continuous self-supporting tobacco film or sheet,means for brushing both faces of said web, means for moistening saidweb, and means for removing said web from said surface.

6. Apparatus for forming self-supporting continuous tobacco films andsheets comprising a moving substantially impermeable film forming devicehaving a film supporting surface, means supporting said surface. formovement in different spaced planes, means for applying a temporaryliquid wetting agent upon successive portions of said surface whilemoving in one of said planes, a device for applying finely dividedtobacco particles and dust in a continuous layer upon said wettedportions of said surface moving in said last-named plane, means forapplying a spray of an adhesive film forming material upon said layer oftobacco particles and dust adhering to said wetted surface while movingin another plane, a device for applying a layer of tobacco dust and finetobacco particles upon the exposed wet surface of said layer of filmforming material on said surface while moving in another plane, meansfor removing said temporary liquid wetting agent and substantiallysimultaneously drying said tobacco covered film or sheet, means forremoving said composite tobacco film or sheet from said surface, andmeans for dyeing said film or sheet.

7. Apparatus for forming self-supporting continuous tobacco films andsheets comprising an impermeable moving film forming member having afilm supporting surface, means for applying a liquid wetting materialupon successive portions of said moving surface, a device for applyingfinely divided tobacco particles in a continuous layer upon said liquidwetting material on said wetted portions of said moving surface, meansfor applying a spray of a film forming material upon said layer oftobacco particles adhering to said moving wetted surface, a device forapplying a layer of fine tobacco particles upon the exposed wet surfaceof said layer of film forming material on said moving surface, a dryerlocated in the path of travel of said moving surface for drying thecomposite layer thus produced to form a composite continuousself-supporting tobacco film or sheet, a device for removing loosetobacco from the top surface of said web as said-sheet or film is movedout of said dryer by said moving surface, a moisture applying unit,means for providing said unit with a moistening fluid for moistening theupper surface of said dried sheet or film, means for removing saidmoistened web from said surface, a second moisture applying unit locatedbeneath the advancing portion of said film or sheet removed from saidsurface, means for supplying a moistening fluid to said last-named unit,and means for reducing. the moisture content in said moistened tobaccofilm or sheet to between 10 and 15%.

8. Apparatus for forming self-supporting continuous tobacco films andsheets comprising an endless band having an impermeable film formingsurface, driving and driven pulleys for moving said band continuously,means located beneath said band and adjacent the lower lap of the filmforming surface thereof for applying a liquid wetting material upwardlyonto successive portions of said moving lower lap of said film formingsurface, a device located beneath said lower lap of said film formingsurface for applying a heavy load of finely divided tobacco particles ina continuous layer upon said wetted portions of said lower lap of saidmoving surface, means for applying a spray of adhesive film formingmaterial upon said layer of tobacco adhering to said moving wettedsurface, a. device located above and adjacent the upper lap of saidmoving surface for depositing a heavy load of fine tobacco particlesupon the exposed wet adhesive surface of said layer of film formingmaterial on said surface, a dryer located in the path of travel of. saidupper lap of said moving surface for drying the composite layer thusproduced to evaporate said liquid wetting material and form a compositecontinuous self-supporting tobacco film or sheet, means located abovesaid upper lap of said moving surface for removing loose tobacco fromthe heavily tobacco loaded top surface of said film or sheet as saidfilm or sheet is moved out of said dryer by said moving surface, meansfor removing said composite film or sheet from said surface, and meansfor brushing the underside of said film or sheet to remove excesstobacco therefrom.

9; Apparatus for forming self-supporting continuous tobacco films andsheets comprising a moving substantially impermeable film forming memberhaving an upper and a lower lap, means for applying a liquid wettingmaterial and wetting successive portions of said lower lap of saidmoving member, transversely movable means for applying finely dividedtobacco particles in a continuous substantially uniform layer upon saidwetted portions of said lower lap of said moving member whereby saidtobacco particles cling to said wetted member, suction means locatedbeneath said lower lap of said member for recovering' free excess fineparticles of tobacco, means for applying, a spray of a'film formingmaterial upon said layer of tobacco particles adhering to said upper lapof said moving wetted member, a device located above and adjacent saidupper lap of said member for applying a substantially uniform layer offine particles of tobacco upon the exposed wet surface of said layer offilm forming material on said upper lap of said moving member, anddrying means located in the path of travel of said upper lap of saidmoving member for evaporating said liquid wetting material and fordrying the composite layer thus produced to form a composite continuousself-supporting tobacco film or sheet.

10. The method of forming self-supporting continuous reconstitutedtobaccosheets and films comprising applying a liquid wetting material toa substantially imperforate film forming surface, depositing asubstantially uniform layer of fine tobacco particles upon said wettedsubstan tially imperforate film forming surface, coating said layer offine tobacco particles with a thin layer of a film forming material, anddepositing a substantially uniform layer of fine tobacco particles uponthe exposed wet surface of said film forming material to form saidsheets and webs.

11. The method of forming self-supporting continuous reconstitutedtobacco films comprising applying a liquid wetting material to asubstantially imperforate film forming surface, depositing a heavy layerof fine tobacco particles upon said wetted substantially imperforatefilm forming surface, coating said layer of tobacco particles with anadhesive film forming material, depositing a heavy layer of fine tobaccoparticles upon the exposed wet adhesive surface of said film formingmaterial to form composite heavily tobacco particle loaded films, andremoving excess and loose tobacco dust and particles from both faces ofsaid films to complete the formation thereof.

12. The method of producing continuous, self-supporting tobacco sheetsand webs comprising applying a liquid wetting material to a film formingsurface, depositing a substantially uniform layer of finely dividedtobacco upon sadi wetted surface, coating said layer of finely dividedtobacco adhering to said surface with a thin layer of an adhesiveflexible film forming material, depositing a substantially uniform layerof finely divided tobacco upon the exposed wet adhesive surface of saidlayer of film forming material, applying heat to said surface to drysaid composite tobacco web or sheet thus produced and evaporate saidliquid wetting material, and removing excess finely divided tobacco fromthe faces of said composite tobacco sheet or web.

13. The method defined in claim 12 including the steps of expanding saidfilm forming surface beneath said film forming material prior to thedrying of said composite sheet or web whereby to prevent checking andcracking of said sheet or web, and humidifying said resulting sheet orweb to a moisture content between and 15%.

14. The method of producing self-supporting continuous reconstitutedtobacco sheets and films comprising applying a liquid wetting materialto a moving surface, applying finely divided tobacco substantiallyuniformly over said wetted portion of said moving surface, forming adispersion of cellulose glycolic acid, applying said dispersion in athin substantially continuous layer upon finely divided tobacco adheringto said surface and binding said tobacco particles forming said layertogether, applying a substantially uniform coating of finely dividedtogacco upon the wet exposed surface of said cellulose glycolic aciddispersion layer, drying said composite film, humidifying said film tobetween 10 and 15% moisture content and cutting said film into sheets orfilaments.

15. The method of producing self-supporting continuous reconstitutedtobacco sheets and films comprising applying a liquid wetting materialto a smooth moving surface, applying tobacco dust substantiallyuniformly over said wetted portion of said moving surface, said tobaccodust adhering in a substantially uniform layer to said wetted portion ofsaid surface, removing tobacco dust not adhering to said surface,forming a dispersion of cellular gly colic acid, applying saiddispersion in a thin substantially continuous layer upon said tobaccodust adhering to said surface and binding said tobacco particles formingsaid layer together, applying a substantially uniform coating of finelydivided tobacco dust upon the wet exposed surface of said celluloseglycolic acid film, removing tobacco dust not adhering to saidcellulosic glycolic acid dispersion layer, drying said composite film,moistening said films to between 10 and 15% moisture content and cuttingsaid film into sheets or filaments.

16. The method of forming self-supporting continuous composite tobaccosheets and films comprising temporarily adhering a thin substantiallyuniform layer of fine tobacco particles on a film forming surface,coating said layer of tobacco particles with a flexible film formingmaterial having natural adhesive qualities, said material comprising acellulose ether derivative, depositing a layer of fine tobacco particlesupon the exposed wet adhesive surface of said film of cellulose etherderivative, film forming material, drying said film of cellulose etherderivative, and

16 removing said composite tobacco sheets and films from said surface.

17. The method defined in claim 16 wherein said film forming material iscellulose glycolic acid.

18. The method defined in claim 16 wherein said film forming material isa soluble salt of cellulose glycolic acid.

19. The method defined in claim 16 wherein said film forming material iscarboxymethyl hydroxyethyl cellulose.

20. The method of forming self-supporting continuous composite sheetsand films comprising applying a liquid wetting material to a filmforming surface, depositing a layer of fine tobacco particles upon saidwetted surface of said film forming surface, coating said layer of finetobacco particles with a thin film of cellulose glycolic acid, said filmpresenting an exposed adhesive surface, depositing a layer of finetobacco particles upon the exposed wet adhesive surface of said film ofcellulose glycolic acid, and drying said film to form saidself-supporting continuous composite tobacco sheets and films.

21. The method of forming self-supporting continuous composite sheetsand films comprising applying a liquid wetting material to a filmforming surface, depositing a layer of fine tobacco particles upon saidwetted surface of said film forming surface, coating said layer of finetobacco particles with a thin film of cellulose hydroxy glycolic acid,said film presenting an exposed adhesive surface, depositing a layer offine tobacco particles upon the exposed Wet adhesive surface of saidfilm of cellulose hydroxy glycolic acid, and drying said film to formselfsupporting continuous composite sheets and films.

22. The method of forming self-supporting continuous composite sheetsand films comprising temporarily adhering a layer of fine tobaccoparticles upon a film forming surface, coating said layer of finetobacco particles with a thin film of a soluble salt of celluloseglycolic acid, said film presenting an exposed adhesive surface,depositing a layer of fine tobacco particles upon the exposed ,wetadhesive surface of said film of a soluble salt of cellulose glycolicacid, and drying said film to form said selfsupporting continuouscomposite sheets and films.

23. The method of forming self-supporting continuous composite sheetsand films comprising temporarily adhering a layer of fine tobaccoparticles upon a film forming surface, coating said layer of finetobacco particles with a thin film of a soluble salt of cellulosehydroxy glycolic acid, said film presenting an exposed adhesive surface,depositing a layer of fine tobacco particles upon the exposed wetadhesive surface of said film of a soluble salt of cellulose hydroxyglycolic acid, and drying said film to form said self-supportingcontinuous composite sheets and films.

24. The method of forming a self-supporting continuous composite tobaccoweb comprising temporarily adhering a substantially uniform layer oftobacco particles upon a film forming surface, coating said layer offine tobacco particles with a thin layer of a naturally adhesive filmforming material, depositing a substantially uniform heavy layer of finetobacco particles upon the exposed wet adhesive surface of said filmforming material to. heavily load said material with tobacco particles,drying said film forming material to form said composite tobacco web,removing excess tobacco particles from the heavily tobacco particleloaded exposed surface of said web, moistening said web, dyeing saidexposed surface of said moistened web, removing said web from said filmforming surface, drying said web, removing excess to bacco from theother surface of said web, dyeing said last-named surface of said web,and redrying said web to complete it. t

25. The method of forming a self-supporting continuous composite tobaccoweb comprising temporarily adhering a substantially uniform layer oftobacco particles upon a film forming surface, coating said layer offine tobacco particles with a thin film of a dispersion containingcellulose glycolic acid, depositing a substansaid composite tobacco Weiremoving excess tobacco particles from the exposed surface of said web,moistening said Web, dyeing said exposed surface of said moistened web,removing said Web from said film forming surface, drying said Web,removing excess tobacco from the other surface of said Web, dyeing saidlast-named surface of said Web, and redrying said web.

26. The method of forming self-supporting continuous tobacco sheets andfilms defined in claim 11 including the step of expanding said filmforming surface prior to the coating of said layer of tobacco particleson said surface with said film forming material.

27. The method defined in claim 14 including the step of expanding saidfilm forming surface prior to the application of said dispersion ofcellulose glycolic acid over said finely divided tobacco adhering tosaid wetted portion of said surface.

28. The method of forming self-supporting continuous composite tobaccosheets and films upon a film forming surface comprising applying a thinadhesive layer of flexible film forming material on said surface,applying a substantially uniform heavy layer of tobacco dust andparticles upon the adhesive exposed surface of said film of film formingmaterial, drying said tobacco impregnated film, expanding said filmforming surface relative to said tobacco particles and layer of flexiblefilm forming material whereby when dried, said composite tobacco filmsor sheets are substantially free of checks, cracks and voids, andremoving excess tobacco dust from said composite tobacco films or sheetsto complete the formation thereof.

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